Effect of coating process on morphology, bending rigidity and wearability of polyester harness cords

In this article, the harness cords were manufactured by braiding, coating and heat setting at the temperatures of 130 and 195℃, respectively. The film formers used in coating process were poly(butyl acrylate), copolymer size and partial alcoholysis polyvinyl alcohol. The pure film formers' spectra were obtained using in-situ infrared test method on a spectrometer. The scanning electron microscope, bending tester and wearing test device were used to measure the morphology, bending rigidity and wearability of harness cords, respectively. The results showed that the temperature of heat setting changed the molecular structure of coatings, and different influences of temperature on the bending rigidity and wearability of coated harness cords were observed. When the heat setting temperature rose from 130 to 195℃, the bending rigidity of poly(butyl acrylate)-coated harness cord almost kept constant. However, the bending rigidity of copolymer size and polyvinyl alcohol-coated harness cords increased by 33.1% and decreased by 47.4%, respectively. The poly(butyl acrylate) coating presented the best adhesivity to hydrophobic polyester harness cord, and the coated harness cord showed the best uniformity and flexibility as well as higher wearability. After heat setting at 195℃, the wearability of harness cords coated with poly(butyl acrylate), copolymer size and polyvinyl alcohol was increased by 380, 120 and 585%, respectively, when compared with the uncoated one.